Easy-RSA: New Windows Start menu item for Easy-RSA Non-Admin mode

[TinCanTech]

Following from #559, I would like to request a new Windows Start Menu Item:

• Name="Start EasyRSA shell (Non-admin)"

This would be a second version of this:

• https://github.com/OpenVPN/openvpn-build/blob/c107ffdae92c8a72485c6ffda3c384ac31145b7d/windows-msi/msi.wxs#L1148-L1156

The command to be executed is:

• Target="[EASYRSADIR]EasyRSA-Start.bat /NA"

The /NA label is for Non-Admin mode. I am happy to go with any suitable label.

I am not familiar with msi.wxs, which is why this is a feature request and not a PR.

[TinCanTech]

This needs further testing: It may be preferable to use the icon property field "Start in", to set %USERHOMEDRIVE%%USERHOMEPATH%.

Linking: https://github.com/OpenVPN/easy-rsa/issues/1075